364 



AUSTRALASIA. 



from shoals, begins the true "Coral Sea," which is studded, not with rocky- 

 heights, but only with a dangerous labyrinth of coralline masses, and which taken 

 as a whole may be compared to a long submarine bank gradually falling east- 

 wards to a mean depth of 20 fathoms. Here is the true coastline of the Australian 

 continent, and as happens on so many other upraised or submerged seaboards, the 

 parting line between the continental plateau and the abysmal depths of the Pacific 

 Ocean is marked by an igneous chain. The volcanoes, however, of the Coral Sea 

 have all become extinct during the present geological epoch, and none of them 

 are of any considerable size, the largest being Murray Island, which lies within 

 the zone of the Great Barrier Reef. Although so near the Australian mainland 



Fig. 157. — ToEEES Strait. 

 Scale 1 : 7,750,000. 



Oto5 

 Fathoms. 



Depths. 



5 to 25 

 Fathoms. 



25 Fathoms 

 and upwards. 



120 Miles. 



of which it is a geological dependence, this island is distinguished from it by its 

 vegetation. The beach and even the lower slopes of the hills, which rise to a 

 height of 600 or 700 feet, are clothed with a continuous forest of cocoanut jjalms, 

 trees which all travellers assure us were not found in Australia before the arrival 

 of the European immigrants. 



The rampart of reefs forming the outer coastline of Queensland and connecting 

 Australia with New Guinea has a total development of no less than 1,500 miles, 

 without counting minor indentations. It begins at Cape Sandy, where the main- 

 land projects seawards off the convex curve of the east coast, and is at first inter- 

 rupted by broad straits ; but the rocks and shoals soon press closer together, and 

 at last merge in a continuous barrier presenting but few openings accessible to 



